Abstraction Health
Mark Hyman

Does Mark Hyman recommend Vitamin D?

Yes — Mark Hyman has directly recommended Vitamin D.

Published research rates it moderate evidence. Of Mark Hyman's 18 tracked claims, 0 are supported or partially supported by studies on PubMed.

🟡Moderate Evidence

Evidence last reviewed May 2026

18
Tracked claims
0
Supported / partial
20
Research studies

Mark Hyman on Vitamin D18 claims

Mark Hyman
Mark Hyman
Cleveland Clinic Center for Functional Medicine
Direct recommendation

if you want to be a vegetarian no problem make sure to check your homosysteine and your vitamin D and things like that

Extracted claim

Vegetarians following a brain-healthy diet should check their vitamin D levels (among other markers like homocysteine).

Insufficient evidence to assessHigh confidence

None of the 20 provided studies directly address the recommendation for vegetarians following a brain-healthy diet to monitor vitamin D levels or homocysteine. While several studies (PMIDs 33237064, 1…

Mark Hyman
Mark Hyman
Cleveland Clinic Center for Functional Medicine
Direct recommendation

if you want to be a vegetarian no problem make sure to check your homosysteine and your vitamin D and things like that

Extracted claim

Vegetarians following a brain-healthy diet should check their vitamin D levels (among other markers like homocysteine).

Not yet assessedHigh confidence
Mark Hyman
Mark Hyman
Cleveland Clinic Center for Functional Medicine
Evidence-backed claim

the study that just came out about 10 days ago showing if you take the people who are low in vitamin D they have a much worse outcome in covid-19 than the people who have sufficient vitamin D

Extracted claim

Low vitamin D is associated with worse outcomes in COVID-19 compared to people with sufficient vitamin D levels, according to a recent study.

Not yet assessedHigh confidence
Mark Hyman
Mark Hyman
Cleveland Clinic Center for Functional Medicine
Evidence-backed claim

people who are low in vitamin D more likely to get Alzheimer's people who are sufficient vitamin D

Extracted claim

People who are low in vitamin D are more likely to get Alzheimer's disease.

Not yet assessedHigh confidence
Mark Hyman
Mark Hyman
Cleveland Clinic Center for Functional Medicine
Evidence-backed claim

same thing in multiple sclerosis high vitamin D associated with better outcomes

Extracted claim

High vitamin D levels are associated with better outcomes in multiple sclerosis.

Not yet assessedHigh confidence
Mark Hyman
Mark Hyman
Cleveland Clinic Center for Functional Medicine
Evidence-backed claim

the study that just came out about 10 days ago showing if you take the people who are low in vitamin D they have a much worse outcome in covid-19 than the people who have sufficient vitamin D

Extracted claim

Low vitamin D is associated with worse outcomes in COVID-19 compared to people with sufficient vitamin D levels, according to a recent study.

Insufficient evidence to assessHigh confidence

None of the 20 published research items provided address the relationship between vitamin D status and COVID-19 outcomes. The available studies cover vitamin D in contexts such as cardiovascular event…

Mark Hyman
Mark Hyman
Cleveland Clinic Center for Functional Medicine
Evidence-backed claim

people who are low in vitamin D more likely to get Alzheimer's people who are sufficient vitamin D

Extracted claim

People who are low in vitamin D are more likely to get Alzheimer's disease.

Insufficient evidence to assessHigh confidence

None of the 20 published research abstracts provided address the relationship between vitamin D deficiency and Alzheimer's disease risk. The studies cover vitamin D in contexts such as cardiovascular…

Mark Hyman
Mark Hyman
Cleveland Clinic Center for Functional Medicine
Evidence-backed claim

same thing in multiple sclerosis high vitamin D associated with better outcomes

Extracted claim

High vitamin D levels are associated with better outcomes in multiple sclerosis.

Insufficient evidence to assessHigh confidence

None of the 20 published research summaries provided addresses multiple sclerosis (MS) or the association between vitamin D levels and MS outcomes. While several studies examine vitamin D supplementat…

Mark Hyman
Mark Hyman
Cleveland Clinic Center for Functional Medicine
Mechanism discussion

there's type two which is atrophic and these are the people where they have low vitamin D pregnenolone progesterone estradiol testosterone you know on and on the critical supports for this nerve growth factor brain derived neurotrophic Factor B12

Extracted claim

In the atrophic type (type two) of Alzheimer's, low vitamin D is one of the key deficiencies to look for alongside low pregnenolone, progesterone, estradiol, testosterone, nerve growth factor, BDNF, and B12.

Not yet assessedHigh confidence
Mark Hyman
Mark Hyman
Cleveland Clinic Center for Functional Medicine
Mechanism discussion

loss of nutrients like vitamin D uh loss of ngf or bdnf brain derived neurotrophic Factor these are all critical for keeping your brain functioning optimally

Extracted claim

Vitamin D is among the critical trophic/nutritional factors whose loss contributes to brain decline and is important for keeping the brain functioning optimally.

Insufficient evidence to assessHigh confidence

None of the 20 studies provided directly address vitamin D's role in brain function, cognitive decline, or neurological health. The closest relevant study (PMID: 37603263) reviews over-the-counter sup…

Mark Hyman
Mark Hyman
Cleveland Clinic Center for Functional Medicine
Mechanism discussion

there's type two which is atrophic and these are the people where they have low vitamin D pregnenolone progesterone estradiol testosterone you know on and on the critical supports for this nerve growth factor brain derived neurotrophic Factor B12

Extracted claim

In the atrophic type (type two) of Alzheimer's, low vitamin D is one of the key deficiencies to look for alongside low pregnenolone, progesterone, estradiol, testosterone, nerve growth factor, BDNF, and B12.

Insufficient evidence to assessHigh confidence

None of the 20 studies provided address Alzheimer's disease subtypes, the 'atrophic type two' classification framework, or the specific panel of deficiencies (pregnenolone, progesterone, estradiol, te…

Mark Hyman
Mark Hyman
Cleveland Clinic Center for Functional Medicine
Mechanism discussion

loss of nutrients like vitamin D uh loss of ngf or bdnf brain derived neurotrophic Factor these are all critical for keeping your brain functioning optimally

Extracted claim

Vitamin D is among the critical trophic/nutritional factors whose loss contributes to brain decline and is important for keeping the brain functioning optimally.

Not yet assessedHigh confidence
Mark Hyman
Mark Hyman
Cleveland Clinic Center for Functional Medicine
Mechanism discussion

in Alzheimer's it's more likely to be things like MotoX sins or reduced vitamin D or reduced hormonal support or ngf or bdnf things like that

Extracted claim

Reduced vitamin D is one of the factors in Alzheimer's disease that is more likely to be causal compared to other neurodegenerative diseases.

Not yet assessedMedium confidence
Mark Hyman
Mark Hyman
Cleveland Clinic Center for Functional Medicine
Mechanism discussion

in Alzheimer's it's more likely to be things like MotoX sins or reduced vitamin D or reduced hormonal support or ngf or bdnf things like that

Extracted claim

Reduced vitamin D is one of the factors in Alzheimer's disease that is more likely to be causal compared to other neurodegenerative diseases.

Insufficient evidence to assessMedium confidence

None of the 20 published research articles provided address the relationship between vitamin D deficiency and Alzheimer's disease or neurodegenerative disease causality. The studies cover topics such…

Mark Hyman
Mark Hyman
Cleveland Clinic Center for Functional Medicine
Personal anecdote

she had initially had a lot of a type two reduced estradiol progesterone no surprise she was 73 reduced vitamin D poor thyroid all those so all those were addressed um she then improved and she actually went from nine so she was in the ninth percentile on her initial cognitive scores she's now at the 97th percentile

Extracted claim

A patient with cognitive decline had reduced vitamin D (among other deficiencies), which was addressed as part of a comprehensive functional medicine approach, resulting in dramatic improvement in cognitive scores.

Not yet assessedHigh confidence
Mark Hyman
Mark Hyman
Cleveland Clinic Center for Functional Medicine
Personal anecdote

she had initially had a lot of a type two reduced estradiol progesterone no surprise she was 73 reduced vitamin D poor thyroid all those so all those were addressed um she then improved and she actually went from nine so she was in the ninth percentile on her initial cognitive scores she's now at the 97th percentile

Extracted claim

A patient with cognitive decline had reduced vitamin D (among other deficiencies), which was addressed as part of a comprehensive functional medicine approach, resulting in dramatic improvement in cognitive scores.

Insufficient evidence to assessHigh confidence

None of the 20 listed studies directly evaluate vitamin D supplementation as part of a comprehensive functional medicine protocol for cognitive decline or cognitive score improvement. The review on ov…

Mark Hyman
Mark Hyman
Cleveland Clinic Center for Functional Medicine
Passing mention

you look at all your nutritional status right the B vitamins vitamin D vitamin E magnesium zinc copper CoQ10 lipoic acid Omega-3s

Extracted claim

Vitamin D is one of multiple nutrients checked as part of a comprehensive functional medicine assessment for cognitive decline, alongside B vitamins, vitamin E, magnesium, zinc, copper, CoQ10, lipoic acid, and omega-3s.

Not yet assessedHigh confidence
Mark Hyman
Mark Hyman
Cleveland Clinic Center for Functional Medicine
Passing mention

you look at all your nutritional status right the B vitamins vitamin D vitamin E magnesium zinc copper CoQ10 lipoic acid Omega-3s

Extracted claim

Vitamin D is one of multiple nutrients checked as part of a comprehensive functional medicine assessment for cognitive decline, alongside B vitamins, vitamin E, magnesium, zinc, copper, CoQ10, lipoic acid, and omega-3s.

Insufficient evidence to assessHigh confidence

The expert's claim describes a multi-nutrient panel (vitamin D, B vitamins, vitamin E, magnesium, zinc, copper, CoQ10, lipoic acid, omega-3s) used in functional medicine assessments for cognitive decl…

Claims are extracted from publicly available podcasts and videos, attributed to their source, and compared against PubMed research. This is educational information only — consult a healthcare provider before starting any supplement.

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